/* inet_pton() stuff */
#ifndef NS_INADDRSZ
#define NS_INADDRSZ	4
#endif
#ifndef NS_IN6ADDRSZ
#define NS_IN6ADDRSZ	16
#endif
#ifndef NS_INT16SZ
#define NS_INT16SZ	sizeof(unsigned short)
#endif
/* int
 * inet_pton4(src, dst)
 *	like inet_aton() but without all the hexadecimal and shorthand.
 * return:
 *	1 if `src' is a valid dotted quad, else 0.
 * notice:
 *	does not touch `dst' unless it's returning 1.
 * author:
 *	Paul Vixie, 1996.
 */
static int
inet_pton4(src, dst)
    const char *src;
    u_char *dst;
{
    static const char digits[] = "0123456789";
    int saw_digit, octets, ch;
    u_char tmp[NS_INADDRSZ], *tp;

    saw_digit = 0;
    octets = 0;
    *(tp = tmp) = 0;
    while ((ch = *src++) != '\0') {
	const char *pch;

	if ((pch = strchr(digits, ch)) != NULL) {
	    u_int new = *tp * 10 + (pch - digits);

	    if (new > 255)
		return (0);
	    *tp = new;
	    if (! saw_digit) {
		if (++octets > 4)
		    return (0);
		saw_digit = 1;
	    }
	} else if (ch == '.' && saw_digit) {
	    if (octets == 4)
		return (0);
	    *++tp = 0;
	    saw_digit = 0;
	} else
	    return (0);
    }
    if (octets < 4)
	return (0);
    memcpy(dst, tmp, NS_INADDRSZ);
    return (1);
}

#ifdef INET6
/* int
 * inet_pton6(src, dst)
 *	convert presentation level address to network order binary form.
 * return:
 *	1 if `src' is a valid [RFC1884 2.2] address, else 0.
 * notice:
 *	(1) does not touch `dst' unless it's returning 1.
 *	(2) :: in a full address is silently ignored.
 * credit:
 *	inspired by Mark Andrews.
 * author:
 *	Paul Vixie, 1996.
 */
static int
inet_pton6(src, dst)
    const char *src;
    u_char *dst;
{
    static const char xdigits_l[] = "0123456789abcdef",
	xdigits_u[] = "0123456789ABCDEF";
    u_char tmp[NS_IN6ADDRSZ], *tp, *endp, *colonp;
    const char *xdigits, *curtok;
    int ch, saw_xdigit;
    u_int val;

    memset((tp = tmp), '\0', NS_IN6ADDRSZ);
    endp = tp + NS_IN6ADDRSZ;
    colonp = NULL;
    /* Leading :: requires some special handling. */
    if (*src == ':')
	if (*++src != ':')
	    return (0);
    curtok = src;
    saw_xdigit = 0;
    val = 0;
    while ((ch = *src++) != '\0') {
	const char *pch;

	if ((pch = strchr((xdigits = xdigits_l), ch)) == NULL)
	    pch = strchr((xdigits = xdigits_u), ch);
	if (pch != NULL) {
	    val <<= 4;
	    val |= (pch - xdigits);
	    if (val > 0xffff)
		return (0);
	    saw_xdigit = 1;
	    continue;
	}
	if (ch == ':') {
	    curtok = src;
	    if (!saw_xdigit) {
		if (colonp)
		    return (0);
		colonp = tp;
		continue;
	    } else if (*src == '\0') {
		return (0);
	    }
	    if (tp + NS_INT16SZ > endp)
		return (0);
	    *tp++ = (u_char) (val >> 8) & 0xff;
	    *tp++ = (u_char) val & 0xff;
	    saw_xdigit = 0;
	    val = 0;
	    continue;
	}
	if (ch == '.' && ((tp + NS_INADDRSZ) <= endp) &&
	    inet_pton4(curtok, tp) > 0) {
	    tp += NS_INADDRSZ;
	    saw_xdigit = 0;
	    break;	/* '\0' was seen by inet_pton4(). */
	}
	return (0);
    }
    if (saw_xdigit) {
	if (tp + NS_INT16SZ > endp)
	    return (0);
	*tp++ = (u_char) (val >> 8) & 0xff;
	*tp++ = (u_char) val & 0xff;
    }
    if (colonp != NULL) {
	/*
	 * Since some memmove()'s erroneously fail to handle
	 * overlapping regions, we'll do the shift by hand.
	 */
	const int n = tp - colonp;
	int i;

	if (tp == endp)
	    return (0);
	for (i = 1; i <= n; i++) {
	    endp[- i] = colonp[n - i];
	    colonp[n - i] = 0;
	}
	tp = endp;
    }
    if (tp != endp)
	return (0);
    memcpy(dst, tmp, NS_IN6ADDRSZ);
    return (1);
}
#endif /*INET6*/

/* int
 * inet_pton(af, src, dst)
 *	convert from presentation format (which usually means ASCII printable)
 *	to network format (which is usually some kind of binary format).
 * return:
 *	1 if the address was valid for the specified address family
 *	0 if the address wasn't valid (`dst' is untouched in this case)
 *	-1 if some other error occurred (`dst' is untouched in this case, too)
 * author:
 *	Paul Vixie, 1996.
 */
int
inet_pton(af, src, dst)
    int af;
    const char *src;
    void *dst;
{
    switch (af) {
    case AF_INET:
	return (inet_pton4(src, dst));
#ifdef INET6
    case AF_INET6:
	return (inet_pton6(src, dst));
#endif 
    default:
	errno = WSAEAFNOSUPPORT;
	return (-1);
    }
    /* NOTREACHED */
}
